detect close failure on just-written file handles

I audited git for potential undetected write failures.
In the cases fixed below, the diagnostics I add mimic the diagnostics
used in surrounding code, even when that means not reporting
the precise strerror(errno) cause of the error.

Signed-off-by: Jim Meyering <jim@meyering.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/builtin-rerere.c b/builtin-rerere.c
index f6409b93c1..29fb075d29 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -57,7 +57,8 @@ static int write_rr(struct path_list *rr, int out_fd)
 		    write_in_full(out_fd, path, length) != length)
 			die("unable to write rerere record");
 	}
-	close(out_fd);
+	if (close(out_fd) != 0)
+		die("unable to write rerere record");
 	return commit_lock_file(&write_lock);
 }